Objective： To evaluate the short-term clinical outcomes of intracranial germinoma patients treated with craniospinal irradiation （CSI） using helical tomotherapy （HT） system in our center. Methods： Twenty-three p...Objective： To evaluate the short-term clinical outcomes of intracranial germinoma patients treated with craniospinal irradiation （CSI） using helical tomotherapy （HT） system in our center. Methods： Twenty-three patients who were treated with CSI in our center from January 2008 to July 2012 were collected, with an average age of 20. M1 of the patients＇ CSI used the HT system. The total doses were 27-36 Gy/15-20 F （1.5-2 Gy per fraction）, and total local doses were 46-60 Gy/30-50 F （5 fractions per week）. M1 female patients for CSI were treated with left-right parallel-opposed field irradiation to protect their ovarian functions. Median follow-up time was 30.9 months （range, 5-67 months）. The SPSS19.0 software was used, and the overall survival （OS） was calculated using the Kaplan-Meier method. Results： Among 17 patients with assessable tumors, 9 cases （52.9%） were CR, 7 cases （41.2%） were PR, and 1 case （5.9%） was SD. Hematological toxicity was the severest side-effect occurred in the procedure of CSI. The level 1-4 acute leukopenia were 8.7%, 30.4%, 34.8% and 21.7% and the level 1-4 acute thrombopenia were 8.7%, 30.4%, 21.7% and 8.7%, respectively. Conclusions： For primary intracranial germinomas, HT can be used to implement CSI for simplifying radiotherapy procedures, improving radiotherapy accuracy, enhancing protection of peripheral organs at risk （ORA） and guaranteeing therapeutic effects. With the acceptable acute and long-term toxicity, CSI using HT in intracranial germinoma patients can be a safe and alternative mode.展开更多
Objective:To evaluate the dosimetric parameters and radiobiological effects in both irradiated and non-irradiated bystander cells of early-and late-responding normal tissues using three radiotherapy(RT)techniques:Thre...Objective:To evaluate the dosimetric parameters and radiobiological effects in both irradiated and non-irradiated bystander cells of early-and late-responding normal tissues using three radiotherapy(RT)techniques:Threedimensional conformal RT(3D-CRT),Volumetric modulated arc therapy(VMAT),and Helical Tomotherapy(HT).Methods:HaCaT cells,representing early-responding normal tissue with a highα/βratio,and BEAS-2B cells,representing late-responding normal tissue characterized by a lowα/βratio,were irradiated with a 2 Gy across three RT techniques.A water phantom was utilized for treatment planning to maintain uniform target coverage and ensure dosimetric comparability among all RT modalities.Various radiobiological endpoints were analyzed to assess cell responses in both irradiated and bystander cells.Results:Although the dosimetric parameters(D_(95%)≈2.0 Gy,D_(2%)≈2.1 Gy,D_(mean)≈2.0 Gy,HI=0.04-0.35,beam-on time=27-254 s,MU rate=270-1936)were broadly comparable across the three RT techniques,the biological responses differed depending on cell type and irradiation method.HT irradiation induced the most pronounced cellular damage in HaCaT cells,with the survival fraction(SF)reduced to 0.31±0.09 in irradiated cells and cell viability of(93.5±3.7)%in bystander cells.In contrast,for BEAS-2B cells,VMAT predominantly affected irradiated cells(SF:0.36±0.04),whereas bystander responses were more evident following HT irradiation[cell viability:(95.0±6.3)%].These observations likely reflect an interplay between biological variables(such as,cellular phenotype,DNA repair capability,and cell cycle distribution),and physical parameters,including beam delivery characteristics,beam on time and MU rate.Conclusion:These findings may help inform decision-making by radiation oncologists and support the development of individualized RT approaches aimed at maximizing treatment efficacy while minimizing long-term toxicity.展开更多
文摘Objective： To evaluate the short-term clinical outcomes of intracranial germinoma patients treated with craniospinal irradiation （CSI） using helical tomotherapy （HT） system in our center. Methods： Twenty-three patients who were treated with CSI in our center from January 2008 to July 2012 were collected, with an average age of 20. M1 of the patients＇ CSI used the HT system. The total doses were 27-36 Gy/15-20 F （1.5-2 Gy per fraction）, and total local doses were 46-60 Gy/30-50 F （5 fractions per week）. M1 female patients for CSI were treated with left-right parallel-opposed field irradiation to protect their ovarian functions. Median follow-up time was 30.9 months （range, 5-67 months）. The SPSS19.0 software was used, and the overall survival （OS） was calculated using the Kaplan-Meier method. Results： Among 17 patients with assessable tumors, 9 cases （52.9%） were CR, 7 cases （41.2%） were PR, and 1 case （5.9%） was SD. Hematological toxicity was the severest side-effect occurred in the procedure of CSI. The level 1-4 acute leukopenia were 8.7%, 30.4%, 34.8% and 21.7% and the level 1-4 acute thrombopenia were 8.7%, 30.4%, 21.7% and 8.7%, respectively. Conclusions： For primary intracranial germinomas, HT can be used to implement CSI for simplifying radiotherapy procedures, improving radiotherapy accuracy, enhancing protection of peripheral organs at risk （ORA） and guaranteeing therapeutic effects. With the acceptable acute and long-term toxicity, CSI using HT in intracranial germinoma patients can be a safe and alternative mode.
文摘Objective:To evaluate the dosimetric parameters and radiobiological effects in both irradiated and non-irradiated bystander cells of early-and late-responding normal tissues using three radiotherapy(RT)techniques:Threedimensional conformal RT(3D-CRT),Volumetric modulated arc therapy(VMAT),and Helical Tomotherapy(HT).Methods:HaCaT cells,representing early-responding normal tissue with a highα/βratio,and BEAS-2B cells,representing late-responding normal tissue characterized by a lowα/βratio,were irradiated with a 2 Gy across three RT techniques.A water phantom was utilized for treatment planning to maintain uniform target coverage and ensure dosimetric comparability among all RT modalities.Various radiobiological endpoints were analyzed to assess cell responses in both irradiated and bystander cells.Results:Although the dosimetric parameters(D_(95%)≈2.0 Gy,D_(2%)≈2.1 Gy,D_(mean)≈2.0 Gy,HI=0.04-0.35,beam-on time=27-254 s,MU rate=270-1936)were broadly comparable across the three RT techniques,the biological responses differed depending on cell type and irradiation method.HT irradiation induced the most pronounced cellular damage in HaCaT cells,with the survival fraction(SF)reduced to 0.31±0.09 in irradiated cells and cell viability of(93.5±3.7)%in bystander cells.In contrast,for BEAS-2B cells,VMAT predominantly affected irradiated cells(SF:0.36±0.04),whereas bystander responses were more evident following HT irradiation[cell viability:(95.0±6.3)%].These observations likely reflect an interplay between biological variables(such as,cellular phenotype,DNA repair capability,and cell cycle distribution),and physical parameters,including beam delivery characteristics,beam on time and MU rate.Conclusion:These findings may help inform decision-making by radiation oncologists and support the development of individualized RT approaches aimed at maximizing treatment efficacy while minimizing long-term toxicity.
